Traditional means to identify the physiological severity of arterial disease are hampered by their inability to identify atheroma extent and composition. New techniques that identify atheroma in vivo are being developed, however, accurate methodologies for atheroma characterization are hampered, due to the heterogeneous nature of the disease process. Novel acoustic targeting and highlighting agents, such as liposomes, may overcome these problems. Liposomes are phospholipid vesicles enclosing an aqueous space. We have developed a unique methodology that, by process and composition, provides acoustic characteristics of liposomes. This formulation allows modification for antibody conjugation and therapeutic drug incorporation. Preliminary work by this group has been centered on the optimization of formulation, optimization of conjugation, and development of in vitro and in vivo quantitation techniques. This proposal describes a series of protocols to optimize highlighting and enhancing characteristics of these formulations in vitro and in vivo. Robust quantitative methodologies will be utilized. We plan to determine in vitro and in vivo transfection and drug delivery potential of these formulations. We plan to investigate the potential of these formulations to aid other imaging modalities as atheroma enhancement agents. Our long term goals are to determine, quantitate, and characterize the stage, extent, and physiologic severity of atherosclerosis and allow directed therapy to improve physiologic flow following intervention.